public void Push(SingleLinkNode <T> newNode)
{
newNode.Item = default(T);
do
{
newNode.Next = head.Next;
} while (!SyncMethods.CAS <SingleLinkNode <T> >(ref head.Next, newNode.Next, newNode));
return;
}
public bool Pop(out SingleLinkNode <T> node)
{
do
{
node = head.Next;
if (node == null)
{
return(false);
}
} while (!SyncMethods.CAS <SingleLinkNode <T> >(ref head.Next, node, node.Next));
return(true);
}
public void Enqueue(T item)
{
SingleLinkNode <T> oldTail = null;
SingleLinkNode <T> oldTailNext;
SingleLinkNode <T> newNode;
if (!trash.Pop(out newNode))
{
newNode = new SingleLinkNode <T>();
}
else
{
newNode.Next = null;
}
newNode.Item = item;
bool newNodeWasAdded = false;
while (!newNodeWasAdded)
{
oldTail = tail;
oldTailNext = oldTail.Next;
if (tail == oldTail)
{
if (oldTailNext == null)
{
newNodeWasAdded = SyncMethods.CAS <SingleLinkNode <T> >(ref tail.Next, null, newNode);
}
else
{
SyncMethods.CAS <SingleLinkNode <T> >(ref tail, oldTail, oldTailNext);
}
}
}
SyncMethods.CAS <SingleLinkNode <T> >(ref tail, oldTail, newNode);
}
public bool Dequeue(out T item)
{
item = default(T);
SingleLinkNode <T> oldHead = null;
bool haveAdvancedHead = false;
while (!haveAdvancedHead)
{
oldHead = head;
SingleLinkNode <T> oldTail = tail;
SingleLinkNode <T> oldHeadNext = oldHead.Next;
if (oldHead == head)
{
if (oldHead == oldTail)
{
if (oldHeadNext == null)
{
return(false);
}
SyncMethods.CAS <SingleLinkNode <T> >(ref tail, oldTail, oldHeadNext);
}
else
{
item = oldHeadNext.Item;
haveAdvancedHead = SyncMethods.CAS <SingleLinkNode <T> >(ref head, oldHead, oldHeadNext);
if (haveAdvancedHead)
{
trash.Push(oldHead);
}
}
}
}
return(true);
}
public LockFreeQueue()
{
head = new SingleLinkNode <T>();
tail = head;
trash = new LockFreeLinkPool <T>();
}
public LockFreeLinkPool()
{
head = new SingleLinkNode <T>();
}